Question

Define holozoic and saprozoic nutrition.

Answer 1

Hint: Types of Heterotrophic nutrition involving different modes of intake, like ingestion of food and absorption of nutrients.

Complete answer:
Holozoic nutrition refers to the intake of organic food by the process of ingestion (intake of food through the mouth), followed by digestion, absorption, assimilation, and finally egestion (undigested food is removed from the body). Holozoic nutrition is seen in Mammals like Human beings, dogs, frogs, Fish, cats, Horses, etc.
Saprozoic nutrition involves the absorption of simple organic materials and dissolved salt from the surroundings to meet the nutrient requirements of the organism. It involves the direct absorption of nutrients present in the extracellular environment through osmosis. Saprozoic nutrition is commonly seen in Protozoa.

Additional Information:
> Nutrition is a process of intake of food and its utilization for growth, development, and for providing energy to the organism to carry out activities.
> Based on the mode of nutrition organisms can be classified into Autotrophic and heterotrophic.
- Autotrophic Nutrition: Food is produced by the organism itself in the presence of sunlight using raw materials like water and carbon dioxide. Eg. All green plants, autotrophic bacteria, and blue-green algae.
- Heterotrophic nutrition: organisms that cannot synthesize their own food depends on other organisms for their nutritional needs. They depend on plants directly or indirectly. Eg. Animals, fungi, protists, bacteria, mammals, etc.
> Autotrophic organisms contain green color pigments called chlorophyll that help in trapping solar energy for producing food in the form of starch by the process called photosynthesis.
> Saprophytic nutrition Or Saprotrophic nutrition are all the same that involve chemoheterotrophic extracellular digestion of dead and decayed organic substance before ingestion.
> Parasitic nutrition differs from saprophytic nutrition in that the food in parasitic nutrition is digested by the other organism on which the parasite dwells. That is Parasitic nutrition involves feeding on living organisms for the nutrient requirement and saprophytic nutrients involve feeding on dead and decayed organisms. An example of parasitic nutrition is seen in Monera (all unicellular bacteria).

Note: A heterotrophic organism obtains its food from other organisms in three different ways: Holozoic nutrition, saprophytic nutrition, and parasitic nutrition. Saprophytic nutrition is different from saprozoic nutrition. In saprophytic nutrition, the organism depends on the dead and decayed organic materials for their nutritional needs. The digestion in these organisms is carried out outside the body and the organism takes in digested food for absorption and assimilation. Saprophytic nutrition is seen in fungi and bacteria.